Enhancement of susceptibility and the electrical resistivity of organic metals with a small mean free path (original) (raw)

1984, Physica B: Condensed Matter

The electro0ie rrtean free path Of org0nlc metals at agrt3ierlt temperature is small, approximately one lattice eon~:ant. This small mea~ free path requires a reformulation of transport theory, and als0 gives rise to new physical effects. The ". ' .M susceptibility is enhanced ever the Fault value by approximateiy a factor of two, and the resistivity continues to follcw a T:-Iaw and does not saturate even when the mean free path becomes smaller than a lattice constant. A theory is descrihe.d which ac~otmts for these unusual effects. The theeu: is somewhat analogous to polaron theory and makes use of ~i,e quadrattc nature of the eMctr0n-phonoa coupli0g. "l'he electrons axe localized by 'phonon traps' acceuntin~ for the transition to a Curie-llke behavior. Tunneling between these non-degenerate molecular sites gives rise to a "/'Z-law with a coefficient close to that of the i0w-tcmperature state where the conductivity is metallic.